共查询到19条相似文献,搜索用时 46 毫秒
1.
以无锡地区6座采用中空纤维膜MBR工艺的城镇污水处理厂细格栅系统设计为例,介绍了细格栅系统组成和选择影响因素,分析了细格栅水力系统及冲洗系统,并对其实际运行效果进行了分析,可为同类工艺细格栅选择提供参考。 相似文献
2.
3.
张鲲鹏;段冬;刘彦伶;夏圣骥 《给水排水》2025,(3):1-8
针对纳滤在市政给水领域多样化的市场应用需求,对比测试了三款中空纤维纳滤商品膜(HF-1、HF-2、HF-3)和传统平板膜NF270的过滤性能以及对实际水体的处理效果。结果表明,3款中空纤维纳滤膜在孔径分布、表面电荷等理化性质方面具有一定差异。4款纳滤膜均能满足市政给水去除有机物的需求,其中HF-1、HF-3和NF270对三种代表性新污染物的截留率均高于80%。3款中空纤维纳滤膜的水渗透系数均小于NF270,其中HF-2具有较低的无机盐截留率(<30%),较适用于处理低含盐量的水源水,可保留水中的矿物元素;HF-3则表现出高硬度去除率(>88%),可满足硬水软化需求。 相似文献
4.
分别进行了单独净化槽和用中空纤维膜改造后的单独净化槽处理生活污水的试验研究。结果表明:单独净化槽对COD的去除效率在80%左右,对NH+4-N的去除率大约在50%~60%。加膜改造后装置对COD的去除效果可达90%左右或更高,并且可实现90%以上的NH+4-N去除效果。膜对有机颗粒与分子的拦截作用使改造后装置出水COD指标不受冲击负荷的影响。NH+4-N由于需较长的反应时间且无法被膜拦截,出水NH+4-N受冲击负荷影响明显 相似文献
5.
向MBR中投加磁性悬浮颗粒,通过改善污泥混合液特性来控制膜污染,试验结果表明:最佳吸附剂为四氧化三铁/硅藻土复合颗粒,吸附剂的最佳投加量为0.1 g/L;投加复合颗粒的MBR出水的COD、氨氮和硝态氮均优于参比MBR,说明复合颗粒能改善膜出水水质;投加颗粒的MBR膜表面的EPS各组分均低于参比MBR,说明四氧化三铁/硅藻土复合颗粒能有效的吸附污泥悬浮液中的EPS,加强MBR的通量稳定性,从而延缓膜污染,减少膜清洗次数,降低运行成本。 相似文献
6.
7.
纤维悬浮流具有广泛的应用背景.该文指出了研究纤维悬浮流中纤维取向分布的重要性:对于流场对纤维的作用力、纤维间的作用力、纤维的重力、纤维的运动与取向分布特性、纤维悬浮流场的流变特性进行了综述与分析;说明了纤维受力、纤维取向分布和纤维悬浮流流变特性之间存在着内在的联系;阐述了己取得的相关研究成果;指出了现有模型和研究方法与研究结果所存在的不足,给出了该研究领域的发展方向. 相似文献
8.
9.
10.
11.
One of the most limiting factors for the extension and acceptance of MBR filtration systems for municipal and industrial wastewater is the impact of membrane fouling on maintenance, operation and cleaning efforts. One field of action in the European Research Project "AMEDEUS" is the development and testing of MBR module concepts with innovative fouling-prevention technology from three European module manufacturers.This article deals with the performances of the flat-sheet modules by A3 Water Solutions GmbH in double-deck configuration evaluated over 10 months in Anjou Recherche under typical biological operation conditions for MBR systems (MLSS = 10 g/l; SRT = 25 days). By using a double-deck configuration, it is possible to operate with a net flux of 25.5 l/m2.h at 20 degrees C, a membrane air flow rate of 0.21 Nm3/h.m2 of membrane to achieve a stable permeability of around 500-600 l/m2.h.bar. Additionally, it was observed that it is possible to recover the membrane performance after biofouling during operation without intensive cleaning and to maintain stable permeability during peak flows.The evaluated concepts for equipping and operating MBR systems will be applied to several full-scale plants constructed by A3 Water Solutions GmbH. 相似文献
12.
Batch filtration tests were conducted to compare the characteristics of membrane biofouling with regard to nitrification and denitrification. A Modified Fouling Index (MFI) was obtained using a stirred cell tester. The denitrification assays showed higher membrane fouling rates than the nitrification assays. The fouling became worse, not only due to pore blocking resistance, but also from cake layer resistance after denitrification. The Extracellular Polymeric Substances (EPS) concentration and relative hydrophobicity were decreased after denitrification, resulting in floc deterioration. The floc deterioration was assumed to have increased the cake layer resistance in the filtration test. The protein Soluble Microbial Products (SMP) concentration, portion of high molecular weight in carbohydrate SMP and relative hydrophobicity were increased after denitrification, which was assumed to cause membrane pore blocking. The changes in the EPS and SMP characteristics were the main fouling parameters in denitrification. 相似文献
13.
好氧池溶解氧对MBR工艺处理效果及运行能耗的影响 总被引:1,自引:0,他引:1
采用倒置A2/O型MBR中试装置,分别在夏季和冬季,通过控制好氧池DO水平,研究好氧池DO对MBR工艺处理效果的影响.试验结果表明:对于试验原水水质,在夏季,当好氧池DO为0.3~0.4 mg/L时,出水水质能够达到<城镇污水处理厂污染物排放标准>(GB 18918-2002)一级A标准;在冬季,硝化菌对DO的要求较高,必须维持好氧池DO在1 mg/L以上,出水水质才能达到一级A标准.运行能耗分析表明,与好氧池DO为2 mg/L比较,当DO为0.4 mg/L与1 mg/L时,可分别减少供气量17.8%与11.9%. 相似文献
14.
建立了以混凝—超滤—反渗透组合工艺处理MBR出水的研究设备。研究表明,该组合工艺具有分离有机污染物和脱盐效果,对TOC、电导率、CODMn、UV254、浊度、总碱度、总硬度的去除率分别达到93.95%、98.94%、90.69%、99.83%、93.41%、89.21%、97.94%。产水电导率≤10μS/cm,可满足部分行业的纯水使用要求。同时,在线投加7mg/LFeCl3和0.35mg/L聚丙烯酰胺(PAM)时,超滤对浊度、UV254、CODMn的去除率分别为82%、20.5%、32.2%,跨膜压差增长趋势减缓,膜污染速率降低,节约了清洗膜的药剂,延长了超滤膜使用寿命,对反渗透膜也具有保护作用。 相似文献
15.
Three-bore hollow fiber charged nanofiltration (NF) membrane was prepared by interfacial polymerization (IP). The results showed that the flux and rejection of NF membrane prepared in this study increased with the increasing in the operating pressure. The water flux decreased and rejection for obvious dyes increased as the solute concentration increased. The separation factor for mixture of Xylenol orange/NaCl decreased when NaCl concentration in solution increased and could reach to as high as 18. In addition, three-bore hollow fiber charged nanofiltration membrane prepared in this study has excellent stability for strong acid (pH = 3), strong alkali (pH = 11) and high temperature solution (80 °C). 相似文献
16.
Nevel Donald E. 《Power Technology and Engineering (formerly Hydrotechnical Construction)》1994,28(3):169-173
Concial structures have been considered for ice covered waters because they reduce the ice forces by causing the ice sheet to fail in bending rather than in crushing. This paper compares the two theories of Nevel and Ralston with eight available data sets from model tests. Both theories agree reasonable well with the data. The advantage of Nevel's theory is that it predicts the overturning moment and location of the ice forces on the cone. 相似文献
17.
A method for non-mechanistic and non-linear modelling of complex biological processes is presented, using the example of the extractive membrane bioreactor (EMB). The model is based on artificial neural networks (ANN), which are able to predict the state of the process from a combination of reactor operational parameters and natural fluorescence fingerprints. Current as well as historic process operation is included in the ANN input vector, in order to account for lag-times within the reactor system and for biofilm dynamics that are dependent on process history. The model is especially relevant for practitioners, as it does not require assumptions on underlying process mechanisms, and it relies on routinely available operational data and on an easy-to-install, non-invasive, in-situ, on-line monitoring method. Moreover, it focuses on the prediction of overall process performance parameters, which are of immediate relevance in practice. The developed model was able to predict the process state very well. Sensitivity analysis revealed that the main impact on process performance stems from process operation rather than the physiological state of the biological culture, and that in the EMB configuration employed process operation history decisively impacts on the process outcome. 相似文献
18.
The paper discusses the experimental optimisation of both chemical and mechanical cleaning procedures for a flat-sheet submerged membrane bioreactor fed with municipal wastewater. Fouling was evaluated by means of the critical flux concept, which was experimentally measured by short-term flux-stepping tests. By keeping constant most important parameters of the biological process (MLSS, sludge age), two different chemical cleaning protocols (2,000 mg L(-1) NaOCl and 200 mg L(-1) NaOCl) were applied with different frequency and, after approximately 9 months of operation, the criticality threshold was determined under different values of SAD(m) (specific aeration demand per unit of membrane surface area). The weaker and more frequent chemical cleaning regime (200 mg L(-1), monthly) proved much more effective than the stronger and less frequent strategy (2,000 mg L(-1), once every three months). The improvement of performances was quantified by two TMP-based parameters, the fouling rate and the DeltaTMP (difference between TMP values during the increasing and decreasing phase of hysteresis). The best performing configuration was then checked over a longer period by running four long-term trials showing an exponential trend of the sub-critical fouling rate with the imposed flux. 相似文献
19.
PAC-UF工艺的膜污染特性及膜污染物质研究 总被引:2,自引:0,他引:2
针对污水处理厂二级出水在超滤膜(UF)工艺和粉末活性炭-超滤(PAC-UF)工艺中的运行,分析粉末活性炭(PAC)对膜污染的影响,并采用三维荧光光谱分析等方法分析膜污染的主要成分。试验分析表明,两种工艺中UF膜的膜通量均呈下降趋势而后趋于平缓,但PAC-UF工艺的下降趋势相对缓慢,说明PAC可以延缓膜污染的形成,但无法阻止膜污染的发生。根据三维荧光的分析,二级出水中的主要污染物为富里酸类物质和腐殖酸类腐殖质,溶解性微生物代谢产物和腐殖酸类腐殖质是造成可逆污染的物质,该污染物通过物理反冲洗可以被大部分去除;通过对碱洗液和酸洗液的分析,推测在PAC-UF工艺中造成UF膜片不可逆污染的物质为酪氨酸类蛋白质、色氨酸类蛋白质和富里酸类物质,这三种有机物是造成UF膜片不可逆污染的主要原因。 相似文献